BURNING UP: Temps to hit 40°C with heatwave smashing Qld, NSW

IT'S likely a whole lot of Queenslanders were nodding off at their desks after parts of the state's south east were hit with 100 per cent humidity early on Tuesday morning. And it wasn't much better for NSW.

The conditions were so bad in Brisbane, the apparent temperature at three in the morning felt more like an average summer's day at three in the afternoon.

Residents of NSW also suffered through the muggy conditions. The bad news is, the humidity is set to last for much of the week.

Victorians, meanwhile, have a different problem to contend with. Gale force winds could rock much of the state, including Melbourne.

"The Brisbane CBD was about 26C last night. That's 5C above average, which doesn't sound that bad but with the humidity that felt like about 30C which is just yucky," Bureau of Meteorology (BoM) forecaster Annabelle Ford told news.com.au.

WHAT THE WEATHER IS DOING IN YOUR REGION TODAY

QLD

Southeast Coast

Very hot. Partly cloudy. Medium (60%) chance of showers and gusty thunderstorms, most likely during this afternoon and evening. Thunderstorms possibly severe.

Winds northwesterly 15 to 20 km/h tending northwest to northeasterly 20 to 30 km/h in the middle of the day then becoming light in the late evening.

Daytime maximum temperatures 34 to 40.

Darling Downs, Granite Belt

Very hot. Partly cloudy. Medium (50%) chance of showers and gusty thunderstorms in the north and far east, slight (20%) chance elsewhere.

Thunderstorms possibly severe in the north and far east.

Winds north to northwesterly 15 to 20 km/h shifting south to southwesterly 20 to 30 km/h in the afternoon.

Daytime maximum temperatures around 40.

Capricornia

Hot and mostly sunny. Medium (50%) chance of showers and gusty thunderstorms in the south, most likely in the afternoon and evening. Slight (20%) chance elsewhere.

Thunderstorms possibly severe in the south. Winds north to northwesterly 15 to 25 km/h tending north to northeasterly 20 to 30 km/h in the early afternoon then decreasing to 15 to 20 km/h in the evening.

Daytime maximum temperatures 33 to 40.

Central Coast, Whitsundays

Hot. Mostly sunny morning. Slight (20%) chance of a shower or thunderstorm inland during this afternoon and evening. Winds north to northeasterly 15 to 25 km/h.

Winds north to northwesterly 15 to 25 km/h tending north to northeasterly 15 to 20 km/h in the evening then becoming light in the late evening.

Daytime maximum temperatures in the mid to high 30s.

NEW SOUTH WALES

Northern Rivers

Hot inland. Partly cloudy. Slight (30%) chance of a shower or thunderstorm in the north during this afternoon and early evening.

Light winds becoming northwesterly 15 to 20 km/h in the morning then tending northwest to northeasterly in the evening. Daytime maximum temperatures in the mid to high 30s.

Mid-North Coast

Hot inland. Cloud clearing. Patchy fog in the south early this morning. Light winds becoming northwest to southwesterly 15 to 25 km/h in the middle of the day then becoming light in the evening.

Daytime maximum temperatures 33 to 38.

Bureau of Meteorology map for Wednesday early morning shows high humidity (bluer areas) close to the east and northern coasts. Picture: Bureau of Meteorology

The Gold Coast, Cape Moreton, Toowoomba and Mackay all sweated through 100 per cent humidity.

The higher the humidity, the more saturated the air is with water. If temperatures are high as well, that means sweat, which normally cools us down, struggles to leave the skin making us feel sticky and drenched.

The humidity made its presence felt at Brisbane Airport with cloud cover at less than 1000 metres. "That's really low and planes can have trouble landing," said Ms Ford.

On Monday, Rolleston, in the Central Highlands, had its hottest February day since records began, peaking at 42.7C. Blackall, 500km away, had its warmest night ever topping out at 37.7C at 3am.

As of Tuesday morning, the temperature in the town hadn't dropped below 30C for more than 24 hours.

Things could stay that way with Queensland and NSW in the grip of a heatwave, "extreme" in places.

"It's not cooling down. It really won't change for the next couple of days," said Ms Ford.

"The heatwave is still going on. Towards the weekend, it will cool down a little bit and be a bit drier so it won't feel as bad but the temperatures are still above average."

The Bureau has forecast an extreme heatwave for much of central and coastal Queensland stretching into Wednesday; a severe heatwave for the rest of the state and northern NSW; and a low intensity heatwave as far south as Sydney.

Thursday will continue to see heatwave conditions across much of Queensland and northern NSW. Picture: Bureau of Meteorology

HEATWAVE CONTINUES

By taking common sense measures, most people should be able to cope with a low intensity heatwave.

However, extreme heatwaves are a different matter with the BoM stating they "will impact normally reliable infrastructure, such as power and transport (and) are a risk for anyone who does not take precautions to keep cool, even those who are healthy".

Brisbane will reach 35C on Tuesday rising to 36C on Wednesday with storms likely. Although temperatures will drop it will still be around 33C on the weekend. Humidity will be north of 90 per cent at 4am until the weekend.

West of Brisbane, in regional areas such as Roma, Dalby and Blackall, expect the mercury to head into the 40s. Blackall is forecast to reach 45C on Tuesday.

In Northern NSW, Grafton will top out at 36C on Tuesday and 39C on Wednesday.

The Hunter Valley could reach 40C on Wednesday. Coastal areas should be cooler, with Sydney 27C on Tuesday, and 32C on Wednesday, heading back into the 20s for the weekend.

The city will be humid, reaching into the 80 per cent range. In the western suburbs expect 40C midweek.